1. Technical Field
Aspects of the present invention relate to a case search system, a case database, a case search apparatus, a case search method and a program therefor, and more specifically, to a case search system for searching for a case of a previously designed network that can serve as a reference in the design or operation of a wireless network.
2. Description of the Related Art
Examples of conventional case search systems for network design and operation according to the related art are described in Japanese Patent Laid-Open No. 2005-269238 (Hereinafter, “Patent Document 1”), Japanese Patent Laid-Open No. 08-044641 (Hereinafter, “Patent Document 2”) and Japanese Patent Laid-Open No. 2003-114911 (Hereinafter, “Patent document 3”). Fault analysis is one of the primary tasks performed in network operations. Patent Document 1 describes that at least fault points, fault observation results (or fault phenomena), points of cause, and frequency are registered in a database. The document further describes performing a search among cases of previously designed networks using a fault point and a fault observation result as search keys such that the causes of the fault are presumed. Therefore, cases of network faults are effectively utilized.
Patent Document 2 describes search of history information of network faults accumulated in a fault history database using an error code which is output at the time of a network fault as a key. The error code is an identifier issued by a computer system when a network fault has occurred and is supposed to indicate a point of the fault or a fault observation result as in Patent Document 1. This can contribute to prompt recovery from the fault in a computer network.
Patent Document 3 describes that in equipment design for a mobile communication system, multiple types of parameters, such as radiowave quality and operation quality, are obtained and threshold values corresponding to such parameters are established. And, an advice table that shows measures to be taken when quality has degraded below such a threshold is prepared. When actual quality has degraded, a way of addressing the degradation is retrieved from the advice table, using the degraded quality as a key and output. According to this technique, it is possible to optimize the parameters in the equipment design for a mobile communication system.
Patent Documents 1-3 all disclose a system or method for searching for a case which can be used as a reference in design or operation, from among past cases or expected typical model cases. And Patent Documents 1-3 all utilize information about an observation result, such as the point of a failure, the phenomenon of a fault itself, or ongoing quality degradation, as a key for search. Patent Documents 1-3 thus enable retrieval of a case of a previous network design having a similar phenomenon or fault that can serve as a reference for a subject matter under consideration.
As mentioned above, the techniques described in Patent Documents 1-3 use a fault observation result, such as a fault point or quality degradation, as a search key. In the design and operation of a wireless network, however, there is a problem that a case which does not serve as a reference may be searched just because it has a matching characteristic of a fault point or fault observation result. Or conversely, there is another problem that a case which serves as a reference cannot be searched only because it does not have a matching characteristic of a fault observation result.